Apparatus for making serpentine tube heat exchanger by twisting one or more runs



1 2t 8% 0 m 8w 9mm T S 4 P 1958 H. H. CHARLTON APPARATUS FOR MAKING SERPENTINE TUBE EXCHANGER BY TWISTING ONE OR MORE RUNS Filed March 1, 1954 IN VEN TOR.

HARRY H. CHARLTON ATTORNEY Sept. 9, 1958 H. H. CHARLTON 2,851,082 APPARATUS FOR MAKING SERPENTINE TUBE HEAT EXCHANGER BY TWISTING ONE OR MORE RUNS Filed March 1, 1954 4 Sheets-Sheet 2 IN VEN TOR.

HARRY H. CHARLTON ATTORNEY p 9, 1958 I H. H. CHARLTON 2,851,082

APPARATUS FOR MAKING SERPENTINE TUBE HEAT 4 EXCHANGER BY TWISTING ONE ORMORE RUNS Filed March 1, 1954 4 Sheets-Sheet 3 Illl: A

IN VEN TOR.

HARRY H. CHARLTON ATTORNEY H. CHARLTON 2,851,082 APPARATUS FOR MAKING SERPENTINE TUBE HEAT EXCHANGER BY 'rwrswme om; OR MORE RUNS Sept. 9, 195's 4 Sheets-Sheet '4 Filed March 1. 1954 INVENTOR. HARRY H. CHARLTON ATT ORNE Y United States Patent APPARATUS FOR MAKING SERPENTINE TUBE HEAT EXCHANGER BY TWISTING ONE OR MORE RUNS Harry H. Charlton, Louisville, Ky., assignor to Reynolds Metals Company, Louisville, Ky., a corporation of Delaware Application March 1, 1954, Serial No. 413,345

6 Claims. (Cl. 153-78) In making a multi-layer condenser, it has been pro posed? to provide a serpentine tubing embracing at least two successive sections and a connection, including at least one return bend, bridging the space between sections, each section having straight runs extending longitudinally between its front and rear ends; to twist the last or end run of the first section to rotate the adjacent connection and the second section from 45 to 135 relatively to the first section; and to twist the first or adjacent end run of the second section to rotate it from 135 to 45 relatively to said connection and first section and in a direction such as to bring both sections into spaced parallel face-to-fac'e relationship.

The present invention relates to this method and has, for its principal object, the provision of a novel apparatus for performing the twisting operations. I

Another object is the provision of a novel apparatus which will perform the twisting operations both rapidly and accurately.

Another object is the provision of a tube twisting machine of simple construction which is inexpensive to manufacture and easy to operate.

The present invention resides in a tube twisting apparatus having spaced and aligned vises constructed and arranged to grip an end run of the serpentine and to rotate relatively to each other about the long axis of that run so as to twist it. In so doing, the tubing on one side of the run is rotated, as a unit, relatively to the tubing on the other side thereof. With, say, 90 rotation, the preceding and succeeding tubing form a 90 corner where they meet. By similarly rotating an adjacent straight run, the preceding and succeeding tubing form layers in spaced parallel face-to-face relationship.

We prefer to have one mechanism perform the first or corner-forming operation and, due to the change in shape of the tubing assembly, to have another mechanism perform the second or layer-forming operation; but one machine may perform both operations. We also prefer to have only one pair of vises on each machine; but one machine may be equipped with more than two vises to perform more than one twisting operation at the same time.

The jaws of the vises may be reduced in outside di mensions to enable them to pass between adjacent runs of tubing. Also, the vises may be adjustably mounted for movement toward and away from each other, to accommodate serpentines of different sizes. The power for operating and rotating the vises maybe conveniently supplied by a manually or automatically controlled fluid motor.

In conjunction with the vises, supports are provided for those parts of the serpentine extending beyond the vises, these supports including a fixed support operating in conjunction with the fixed vise and a pivoted support operating in conjunction with the rotatable vise.

The invention will be described in greater detail in connection with the accompanying drawings illustrating pre- Patented Sept. 9, 1958 atthe left side of Figure 1 and the bottom side of Figure 2;

Figure 5 is a sectional view taken on line VV of Figure 1;

Figure 6 is a sectional view of another machine for carrying out the second twisting operations, this view corresponding to one taken on line VIVI of Figure 7;

Figure 7 is a plan, view of. said second machine;

Figures 8 to 1.2 are diagrammatic views illustrating the twisting operations, Figure 8 being a plan view of a planar serpentine tube, Figures 9-10 being edge views of the tube duringand after the corner forming operations and Figures 11-12 indicating the tube during and after the final layerforming operations; and

Figure 13 ,is a diagrammatic illustration of a fluid pressure operating mechanism.

First machine Figs. 1-5

Referring to the drawing, a base 1 is provided having a keyway 2 therein, and a base plate.3, having a key 4 fitting in the keyway, is suitaby clamped thereto. This base plate carries a post 6 which supports a bearing 7 at its. top. Mounted upon post 6, as by welding, is a side plate 8 suitably braced by a welded bracket 9, and having laterally elongated slots 11, four being shown. Plate '8 has a groove or slot 12 in one face, and an angle block 13 (Figs. 2 and 5) has a rib 14 received in the groove and is adjustably held on plate '8 by recessed head bolts 15 passing through slots 11 into tapped holes in the angle block. This construction allows the angle block to be adjusted laterally on the plate 8. The purpose of this structure will be presently described.

A shaft 16 is journalled in bearing 7 for rotation from a planar serpentine tube receiving position to a twisted tube position. This shaft carries a spacer 17 and a rigid frame composed of block 18, transversely spaced outer and inner longitudinal bars 19 and 23 and longitudinally spaced outer and inner cross bars 22 and 21. Bar 23 is bolted to bars 22 and 21, which are welded to angle bar 19, the latter being welded to block 18 which is keyed to shaft 16 so that this frame rotates with the shaft. This frame provides a marginal support for a planar serpentine; hence angle bar 19 has a suitable liner or fiber or other soft material while bar 23 is composed of fiber and provided with tube receiving grooves 24.

Another marginal support for the tubing is provided on the same side of the machine but on the other side of shaft 16 by an outer longitudinal. angle bar 27 which is lined like bar 19 and aligned with bar 19 in the tube receiving position. Bar 27 is rigidly supported by welding it to block 25 which is welded to post 6.

On the opposite side of the machine, outer longitudinal angle bar 46 corresponds in function and arrangement to bar 27. It is welded to post 45 which is welded to base plate 28. Bars 27 and 46 provide a fixed support or table for one or more sections of a serpentine tube.

Also on the opposite side of the machine the base plate 28 carries posts 29 which support the opposite bearing member 31 in which the opposite shaft 32 is journalled for the same rotation as shaft 16.

This shaft 32 carries a spacer 33 and a rigid frame, corresponding to the other rigid frame which includes posts 19 and 21-23, and composed of a shaft-keyed. disc or plate 34 to which a block 35 is welded, transversely spaced outer and inner longitudinal bars 36 and 39, and

longitudinally spaced outer and inner cross bars 38 and 37. The parts of this frame are secured and lined like the corresponding parts of the corresponding frame and fiber part 39 has grooves 41 which are aligned with grooves 24.

The corresponding rigid frames are rigidly joined together by intermediate links 42 and 43, one rigidly connecting the inner cross bars 21 and 37 and the other, the outer cross bars 22 and 38. By detaching bars 42 and 43 from 21 and 22, the machine can be widened or narrowed, as desired, and the bars then reconnected. These frames cooperate to form a rotatable table 50 which, as a unit, pivots about the axis of shafts 16 and 32. The grooved bars 23, 39 receive the straight runs of the coil and maintain them properly spaced and positioned. The return bends of the coil are received on angle bars 19, 36, the fiber liners serving to prevent injury to the coil. The edge of angle bar 36 is cut away at 36' not only to accommodate the extended end A which must project beyond bar 36 but also to provide a mark or gauge indicating the correct position of the coil on the table and thus insuring that the inter-layer return bends will always be properly located with respect to the inlet and outlet ends of the coil.

The angle block 13, has suitable tapped bores in its flange 48 and an abutment block 49 (Fig. is positioned on dowels 51 in the flange 48 and is bolted thereto by bolts 52. A movable vise block 53 is bolted to flange 48 by a shoulder bolt 54 acting as a pivot, and a shouldered guide bolt 55 passing through arcuate slot 56. Mounted on the blocks 49, 53 are the vise jaws 57, 58 respectively, each being bolted to the top of its respective block and being held in position by a key 59. It will be observed the jaws have reduced portions or fingers 61, 62 in which are located complementary sockets 63a and 63b, adapted to clamp a tube 47 therein, the sockets 63a, 63b being located substantially in coaxial alignment with the shafts 16 and 32. These fingers 61, 62 are small enough to enter between adjacent straight runs of coil 47 when the jaws are in open position, the opening movement being limited by an adjustable stop screw 64 threaded into plate 8 and held by a lock nut.

A hydraulic cylinder 65 is bolted to block 49 and a bore 66 in the block receives an extension rod 67 of the piston which passes therethrough. Block 53 has an aligned bore 68 which receives the rod 67, and a cross pin 69 in slot 71 passes through the rod to operatively connect the block 53 with the rod 67. It will be seen that upon movement of the rod 67 to the right as seen in Figure 5 the block 53 swivels to open the vise jaws. Movement of the rod 67 to the left causes the block 53, and jaw 58 to clamp a tube run in the sockets 63a and 63b, so the tube is held against turning. The jaws 57, 58 and operating connections constitute a dead center vise located adjacent the shaft 16 of the pivoted table, and indicated generally by the numeral 70.

The live center vise structure includes an abutment block 71 (Fig. 3) suitably fastened to block 35 and carrying a jaw 72; and a pivoted vise block 73 pivoted upon block 35 in a manner similar to block 53, and carrying a jaw 75, the jaws providing complementary sockets 76a and 76b. A hydraulic cylinder 77 mounted upon abutment block 71 has a rod 78 extending from its piston through block 71 into block 73 and connected to pivoted block 73 by cross pin 79 so as to operate the jaws to grip or release a tube run. This live center vise is designated generally by the numeral 80. A hooked arm 81 extending from block 35 carries a set screw 82 which limits opening movement of the vise jaw. As the construction of the live center vise is similar to the dead center vise, a more detailed description of the former is not deemed necessary. It should be observed that the disc 34 carries the live center vise designated generally by the numeral 80, and when the disc is rotated the live center vise is rotated about the gripped tube and shaft 32 as the center. Thus, when the live center vise and dead center vise 70 are gripping a tube run, rotation of the live center vise will twist the tube run.

The mechanism for rotating the live center vise now will be described. A post 83 on the base plate 84 has a reduced portion which receives the clevis 85 on one end of a hydraulic cylinder 86 and is swivelled on clevis pin 87. The disc 34 has a crank pin 88 extending therethrough, which receives the eye end of a piston rod 89 extending from the hydraulic cylinder. When the hydraulic piston moves to the right as seen in Figure 2 or 3 the disc 34 and the live center vise thereon are rotated counter clockwise and the supporting pivoted table 50 also is rotated counter clockwise. When a tube is being gripped by the live center and dead center vises this rotation of the live center vise twists the run held between the vises. A stop block 91 on the disc 34 is engaged by an adjustable stop screw 92 to limit counter clockwise rotation to the vise to an amount required to produce a ninety degree twist in the tube, allowing for the spring back of the tube. On the return movement a stop block 93 on the block 35 of the disc engages adjustable screw 94 on post 95 to stop the disc in idle position.

The fluid pressure operating mechanism is shown diagrammatically in Figure 13 and comprises hydraulic valves 96 and 97 having operating levers 98 and 99 respectively. These valves are supplied with a suitable fluid, such as oil or air under pressure, by a pipe 101. From valve 97 pipes 102 and 103 lead to the ends of cylinder 86. A conduit 104 leads from valve 96 to the corresponding ends of cylinders 65, 77 and a conduit 105 leads from valve 96 to the other ends of cylinders 65, 77. It will be seen that operation of lever 98 of valve 96 in one direction will operate cylinders 65, 77 in the direction to close the vises, and operation of lever 98 in the other direction will open the vises. Similarly, operation of lever 99 of valve 97 in one direction will operate cylinder 86 to rotate the disc 34 in one direction while operation of this valve in the opposite direction will operate cylinder 86 to rotate disc 34 in the opposite direction.

The operation of the apparatus now will be described in connection with the diagrams shown in Figures 8, 9 and 10. In Figure 8 a sinuous coil 47 is shown comprising a single length of tubing having the inlet end A, outlet end B, and formed into a series of thirty-six straight runs and return bends lying in one plane. To facilitate the explanation certain runs are designated by the numbers 110, 112, 113, 124, and 136, corrresponding to the first, twelfth, thirteenth, twenty-fourth, twenty-fifth and thirtysixth runs, respectively, and the return bends are designated as 112, 113, 124' and 125.

With the apparatus in the position shown in Figures 1 to 3, the coil 47 is laid upon the fixed and rotatable tables with the inlet end A extending past the edge 36' as shown in Figure 2. In this position the various straight runs enter the grooves 41, 24, and the run 113 enters between pairs of jaws 75, 72 and 61, 62, so as to lie within the confines of sockets 76a, 76b and 63a, 63b. It will be noted the return bends lie on the angle bars 36, 19, 46, 27. Cylinders 77, 65 now are operated to bring the jaws of vises 70, 80 together to clamp the thirteenth run 113 in the sockets. Now, cylinder 86 is operated to rotate the live center vise 80 and the rotatable table 50 counter clockwise through about ninety degrees, the engagement of extension 91 with stop screw 92 stopping the rotation. This rotation twists run 113 between the clamping points of vises 70 and 80, and the amount of twist may be adjusted by screw 92 to provide for the spring back. The vises 70 and 80 then are released, and then cylinder 86 is reversed to return the rotatable table 50 and vise 80 to their initial position. This produces a coil in the form of an L-shape as shown in Figure 9, in which return bend 112' has been rotated to lie in a plane perpendicular to the plane of return bend 113'.

The coil then is lifted from the machine and inverted so that end B now projects beyond edge 36', and twentyfourth run 124 lies between the jaws of the vises. The jaws then are closed and live vise 80 and the table 50 are rotated counter clockwise to the perpendicular position. The vise jaws then are released and the live center vise 80 and table 50 are returned to the initial position. the Z-shape thus formed is shown in Figure 10, where return bend 124 lies perpendicular to return bend 123. In these operations the middle tier of the coil has been formed first and comprises runs 113 to 124.

Second machine Figs. 6-7

The remaining operations, as illustrated in Figures 11 and 12, are carried out on the machine illustrated in Figures 6 and 7, and as this machine is similar to that shown in Figures 1 to 5, only the differences will be described in detail. As illustrated, the rotatable table 50 has been transposed to the left hand side (compare Figs. 2 and 7) the live center vise 80 remaining at the same position with the movable and fixed jaws and the operating cylinder 77 transposed. The dead center vise 70 remains in the same position with the fixed and movable jaws and the operating cylinder 65 transposed. These transpositions involve changes in the supporting structures which need not be described in detail, as they will be obvious to those skilled in the art. The cylinder 86 for rotating disc 34, and the stops 93, 91 also have been transposed.

A modified form of fixed table 150 is employed and comprises base plates 152, 153 having upright angle bars 154, 155 welded thereto, and cross blocks 156 welded to the angle bars. A grooved fiber block 157 spans the cross blocks. Longitudinal angle bars 158, 159 braced by suitable struts 160 extend from angle bars 154, 155, and near their ends carry cross blocks 161 upon which is positioned the grooved bar 162.

The operation of this modification is best described in connection with Figures 11 and 12. The Z-shaped coil, shown in Figure 10 is positioned on fixed support 150 so that end B extends downward as viewed in Figure 7 so that the twelfth run 112 is received in the sockets of vises 70, 80. The vises are closed to clamp the run 112 and vise 80 is rotated clockwise as viewed in Figure 6 to rotate bend 111' through ninety degrees, to the position shown in dotted lines in Figure 11, thus completing two tiers of the coil. The vises 70, 80 then are released and vise 80 and table 50 are returned to initial position. The coil then is repositioned as shown'in full lines in Figure 12 so that the twenty-fifty run 125 is located in the vises, the vises are closed to clamp the run, and the vise 80 is rotated to turn run 125 through ninety degrees, bringing the coil to the form shown in dotted lines. The vises then are released, and the vise 80 and table 50 returned to initial position.

It will be observed that the grooved blocks 162, 157 support the coil during the twisting operations, and that the part of the coil received on support 50 is rotated. That is, in Figure 11 the runs 110 to 112, and in Figure 12 the runs 136 to 125 are received on support 50 and rotated. Where the coil is to be inserted into fins having apertures closely fitting the surfaces of the coil runs, it is important that the runs be maintained free from irregularities on thier surfaces, and that they be maintained straight and true. The provision of the grooved bars for holding the runs aligned, and of the fibre supporting surfaces assists in preventing deformation or damage to the tubes during the twisting operations.

It will be appreciated, that, in both machines, the stationary vise or tube holder may be of the fixed or nonmovable jaw type since. it functions primarily to engage opposite sides of its straight run and to hold that run in the rotational axis while the other vise twists that straight run about that common axis.

We claim as our invention:

1. An apparatus for rotating pre-formed, reverse bends at the ends of a length of tubing comprising: a base; a first bearing member mounted on said base; a second bearing member mounted on said base in axial alignment with said first bearing member; a tube supporting table journalled in said bearing members for rotating movement and adapted to receive a serpentine tubing to be bent; means adjacent one bearing member for holding said length of tubing adjacent the reverse bend at one end of said length of tubing against rotation; means adjacent th other bearing member rotatable with said table for engaging and rotating said length of tubing adjacent the reverse bend at the other end thereof to twist said length of tubing; and means for rotating said table and latter means to dispose said reverse bends at the ends of the length of tubing in angular relation.

2. An apparatus as specified in claim 1 wherein said means adjacent one bearing member comprises: a vise below said table having a fixed jaw with a reduced portion adapted to extend above said length of tubing, on said table and having a cylindrical socket therein axially aligned with said bearing members; and a movable jaw with a reduced portion adapted to extend above said length of tubing and having a complementary cylindrical socket therein; said sockets being adapted to receive and grip the length of tubing to hold the reverse bend; and means for moving said movable jaw to and from gripping position.

3. An apparatus as specified in claim 1 wherein: said table is carried adjacent said other bearing member by a disc rotatably journalled in said other bearing member; said means adjacent said other bearing member comprises a vise carried on said disc; fixed abutment means carried by said base; and stop means carried by said disc adapted to engage said abutment means to limit rotation of said disc.

4. An apparatus for twisting a terminal run of a section of serpentine tubing having a plurality of straight runs connected by reverse :bends comprising: a support for said section; a base pivotally mounting said support for rotary movement about an axis corresponding to the longitudinal axis of said terminal run with said section properly positioned on the support; a stationary vise supported by said base and having means operatively disposed for gripping one portion of said terminal run coaxially of said axis; a second vise in fixed relation with said support for rotation therewith and having means operatively disposed for gripping another portion of said terminal run spaced from said portion coaxially of said axis; and means for rotating said support and the vise fixed thereto through substantially 5. Apparatus as defined in claim 4 including: fluid pressure means for actuating said second vise and mounted on said support for rotation therewith.

6. Apparatus as defined in claim 5 including: fluid pressure means for actuating the first vise; and control means for actuating both of said fluid pressure means simultaneously.

References Cited in the file of this patent UNITED STATES PATENTS 718,035 Tindel Jan. 6, 1903 1,004,492 Stock Sept. 26, 1911 1,740,792 Strachauer et al. Dec. 24, 1929 1,943,557 Ruthenburg et a1. Jan. 16, 1934 2,082,580 Johnson June 1, 1937 2,357,873 Bower Sept. 12, 1944 2,450,876 Blumensaadt et a1. Oct. 12, 1948 2,522,499 Berglund et a1 Sept. 19, 1950 2,628,653 Sherman Feb. 17, 1953 2,632,482 Lincoln Mar. 24, 1953 

